[Eeglablist] importing dat files back into Neuroscan

[jimcav at email.arizona.edu]

Maria,
  I did the same thing a while ago, but I learned to embrace the odd time axis. 
If you export your .set data into .dat or .txt files, Neuroscan will read them
in and assume that the time starts at 0.  If you just work that into your
equation in your .tcl script, you can use the peak picking normally. For
instance, if your -500ms to +1500ms epochs were sampled at 1000Hz, you could
just pick the voltage at 0ms by asking for the voltage at ‘500ms’.

I used the following to import data from only the Cz electrode (1) saved at
500Hz (500), with 900ms of data (0-451) from (30) epochs:

IMPORTAVG "$path\\902_m1crnCue_CSD.dat" P 1 500 0 451 30 N
SAVEAS "$path\\902_m1crnCue_CSD.avg"
CLOSEALL

Even though this was actually -400 to +500ms, I looked for the response-locked
N2 from ‘600-750ms’ (actually 200-350ms)

(Note: Try this PAUSE command – it lets you check out the placements before
peak selection!)

OPENFILE {$path\\902_m1crnCue_CSD.avg }
CLEARALLMARKERS
PEAKDETECTION_EX "Min" Y 600 750 MIN N x N N USER RED { ALL }
PEAKDETECTION_EX "Max" Y 550 700 MAX N x N N USER Blue  { ALL }
PAUSE "Examine the Peak!"
UPDATECHANGES
SAVEPEAK "$path\\902_m1crnCue_CSD.dat"
CLOSEALL


Jim Cavanagh
PhD Student
Psychophysiology Lab
University of Arizona


Hi Eeglab superstars,


This is actually a question about importing a dat file from EEGLAB back into
Neuroscan.  I figured posting to this listserv would be worth a try, since I
think many of you are probably users of both.
I have many dat files to import back into Neuroscan because I want to peakpick
in this program, but when I try to run a batch file doing this, the x axis,
which is in time, never gets imported correctly.  I think this may be because I
am going from -500 prestimulus onset to 1500 ms post stimulus onset...and
Neuroscan doesn't understand the negative values when I try to import via a
bathc file...but I am not sure.  Anyway, when I do it by hand in Neuroscan, it
actually works (going to open file, open dat, then typing in the various
parameters) but this is time consuming, as I have many files.  I was wondering
if anyone had found another solution using the batch files for Neuroscan or if
people preferred other programs to use for peakpicking of ERPs
Here is my batch file for the importing of the avg file....it's the -.5 that I
appear to be having trouble.  I tried changing it to, -5, -500, -.05 etc, but
none of these worked.

set path "C:\\251\\"
set subject {8012}
set condition {_newbaseline_n100_p200}

foreach element $condition {
        foreach name $subject {

IMPORTAVG "$path$name$element.dat" P 124 750 -.50 1501 1 N
SAVEAS $path$name$element.avg
  CLOSEALL}}

Any thoughts on the matter would be greatly appreciated!
Thanks,
Maria Jalbrzikowski